1. Field of the Invention
The present invention relates to a device of a node and method for beacon scheduling in an ad-hoc network and a data transmitting method thereof, and more particularly, to a beacon scheduling method for dynamically changing a beacon cycle of a node and a node selecting method for minimizing a data transmission delay.
This work was supported by the IT R&D program of MIC/IITA.[2005-S038-02, Development of UHF RF-ID and Ubiquitous Networking Technology]
2. Description of the Related Art
According to Zigbee network topology, each of nodes in a network system is classified into a Zigbee coordinator (ZC), a Zigbee router (ZR), and a Zigbee end device (ZE).
The ZC is located at the top on a tree structure and manages the entire tree. The ZR is a sub node of the ZC and communicates with the ZC using a beacon received from the ZC. Also, the ZR generates its own beacon, which is free of collision with the beacon of the ZC, to communicate with its sub nodes.
The ZE is located at the bottom on the network topology and performs data communication using the beacon received from the ZR or the ZC. A ZR adjacent to the ZC or a sink node must perform frequent data communications in order to transmit data from ZEs to the sink node. Therefore, a sensor node with limited power such as the ZR rapidly uses up its power and thus fails to serve as a node.
In place of the failed sensor node, another substitute node adjacent to the ZC or the sink node may be used to create a new route. However, the substitute node also loses its function immediately, making it impossible to transmit data from the ZEs to the ZC or the sink node.